Organic substances in the form of vapours or particles are to a large extend created as undesired secondary products in connection with many production processes within the industry. As examples can be mentioned preparations and use of lacquer and paint, cereal and feedstuff, metal and plastic, tar and asphalt, tanneries, incinerating plants, bio-gas plants, market gardens, agriculture and also large parts of the food industry.
Today severe demands are made to the hygienic and health conditions regarding the work spots/sites as well as to the surrounding milieu. The organic substances mentioned are, however, more or less injurious to health, and furthermore many of them have a foul smell. It will therefore normally not be allowed to leak air contaminated with such organic substances to the surroundings. Purification of the air must take place before that.
This purification normally takes place by filtering he contaminated air in, for example, grease filters and carbon filters. Mechanical filters of this type are, however, rather expensive in use, since they need to be cleaned at short intervals and frequently have to be replaced. Furthermore, the filters cannot fulfill the high hygienic standard, which, for example, is required within the food industry, and to this can be added that filters, which, as an example, are filled with grease, must be considered as extremely flammable.
Furthermore, it is known technology to use ozone for removing especially foul smell from air contaminated with organic substances. The ozone is normally created in an electric arc in the form of the so-called corona-ozone, whereby there as a unfortunate side effect is created NOX, which is damaging the environment and health injuring to human beings.
In other cases different chemicals for decomposing and destroying the organic substances are added to the contaminated air. The chemicals can, however, themselves contribute to contamination of the air, and the same applies to those products which are created by the chemical reactions purifying the air.